If more than one obscuration is occurring at the same time, they should be entered in which order?

When multiple obscurations, such as fog, haze, or smoke, are occurring simultaneously, the correct approach is to enter them in order of decreasing dominance. This means that the most significant obscuration impacting visibility should be recorded first.

The reasoning behind this choice is to provide a clear and effective representation of the conditions experienced at the observation location. By prioritizing the more impactful obscuration, it ensures that anyone reading the observation report can easily understand which factor primarily affects visibility at that moment.

For example, if heavy fog is present with light smoke, indicating the fog first provides a more accurate picture of the most critical weather condition affecting navigation and safety. This method helps pilots and other aviation professionals assess the weather more quickly and accurately, which is vital for safe decision-making.

Entering obscurations based on their intensity or any other characteristic could lead to ambiguity or confusion, potentially compromising safety and situational awareness. Therefore, the guideline for reporting obscurations emphasizes the importance of the order based on their decreasing dominance.